POS0207-HPR FEAR OF MOVEMENT MEDIATES THE RELATIONSHIP BETWEEN PAIN CATASTROPHISING AND PHYSICAL FUNCTION IN PEOPLE LIVING WITH AXIAL SPONDYLOARTHRITIS: A CROSS-SECTIONAL MEDIATION ANALYSIS
Authors: P. Rouse, T. Ingram, M. Standage, R. Sengupta
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Axial spondyloarthritis (axSpA) typically affects the axial skeleton and sacroiliac joints causing patients to experience pain, reduced movement, and impaired physical function. A range of treatment options are available to help axSpA patients reduce pain and maintain physical function and thereby enhance health-related quality of life. The European Alliance of Associations for Rheumatology (EULAR) identified activity as integral to the management of inflammatory arthritides, however, the majority of people living with axSpA are not sufficiently active to maintain physical function [1]. According to the Fear-Avoidance Model of Pain, fear of movement and pain catastrophizing contribute to poorer physical function via reduced activity and disuse [2]. Yet to date, no research has tested the theorized mediating role of fear of movement in the relationship between pain catastrophizing and physical function in people living with axSpA. <h3>Objectives</h3> To examine the mediating role of fear of movement in the relationship between pain catastrophizing and physical function in people living with axSpA. <h3>Methods</h3> Participants (<i>N</i> = 98, 70% female, <i>M</i> Age = 45.62 SD 12.16) completed an online survey (December 2020 – May 2021) distributed in the United Kingdom via the National Axial Spondyloarthritis Society (n ≈ 3,500; NASS, 2019). The Tampa Scale for Kinesiophobia (TSK-11) was used to measure fear of movement with participants rating 11-items from 1 (strongly disagree) to 4 (strongly agree). The Pain Catastrophising Scale (PCS) contains 13-items, each rated on a scale from 0 (not at all) to 4 (all the time). Both instruments have shown strong internal consistency in people living with axSpA [3,4]. The Bath Ankylosing Spondylitis Functional Index (BASFI) was used to assess physical function with higher scores indicating poorer function. Data were analysed using IBM SPSS (Version 28). The PROCESS SPSS macro was used, and interpretation made using the percentile bootstrap 95% confidence intervals from 5000 bootstrap samples. Standardised effects with values.01,.09, and.25 represent small, medium, and large effects [5]. <h3>Results:</h3> <h3>Conclusion</h3> Pain catastrophizing is experienced by people living with axSpA and can lead to the avoidance of movement, and as a result, compromised physical function. Our test of the Fear-Avoidance Model showed that pain catastrophizing significantly predicted the physical function of people living with axSpA and that this relationship was mediated by fear of movement. Fear of movement is a modifiable construct that can be a treatment target for health professionals to improve the physical function of people living with axSpA. Identifying modifiable factors that contribute to disease outcomes is critical to improve the care and quality of life for people living with a disease currently without a cure. <h3>References</h3> [1]O'Dwyer T, O'Shea F, Wilson F. Rheum Int. 2015; 35(3):393-404. [2]Vlaeyen JW, Linton SJ. Pain. 2012; 153(6):1144-1147. [3]Swinnen TW, Vlaeyen JWS, Dankaerts W, Westhovens R, de Vlam K. J of Rheum. 2018; 45(3):357-366. [4]Kieskamp SC, Paap D, Carbo MJ, Wink F, Bos R, Bootsma H, et al. Rheum. 2021; 60(10):4476-4485. [5]Cohen J. Psych Bull; Citeseer; 1992. <h3>Acknowledgements</h3> We thank the Bath Institute for Rheumatic. Diseases (BIRD) for funding to support this research. <h3>Disclosure of Interests</h3> Peter Rouse: None declared, Thomas Ingram: None declared, Martyn Standage: None declared, Raj Sengupta Speakers bureau: Abbvie, Biogen, Celgene, Lilly, Novartis, Roche, UCB, Consultant of: Advisory boards for Abbvie, Biogen, Lilly, Novartis, UCB, Grant/research support from: Yes - Abbvie, Celgene, Novartis, UCB.